My bike and others here had this problem... the electrical connection going to the coil(s) works loose. When this happened to mine the bike suddenly coughed and choked so bad I couldn't ride it. So... these connections are under the tank but you can access them by contorting your body enough to be able to look up under the tank. The coils are right there, one on each side. Now look for loose connectors and if needed, re-seat them. Hopefully....vroooooom and away you go.
